Full set of Notes with Fill-Ins - San Jose State University

Chem 155 Unit 1 Page 51 of 3161.1.26 Standard Additions by Linear Regression:Let:V X = volume of unknown analyte solution added to each flaskC X = concentration of unknown solutionV T = final, diluted volumeV S = volume of ‘spike’ added to unknown soln. before dilutionC S = concentration of analyte in spike solutionDilution Calc 1: (V 1 C 1 = V T C T C T = V 1 C 1 /V T )Contribution to concentration of analyte from sample:V X C X /V TDilution Calc 2:Contribution to concentration of analyte from spike:V S C S /V TTotal Signal (sensitivity = k) given that ‘x’ variable is C S .S = kV X C X /V T+ kV S C S /V TSlope = m =kC S /V Tintercept = b =kV X C X /V Twe can get b and m from linear regressionand we want C X … so … b/m = =so : C X =bC SmV XkV X C X /V TkC S /V TV X C X /C SPage 51 of 316